Slide projector for ring magazines

ABSTRACT

A slide projector for use with ring-shaped magazines arranged horizontally for rotation about a vertical axis offset laterally from the horizontal optical axis. As the magazine rotates step by step, an inclined ramp raises the slide which is to be projected so that its bottom edge will clear the rather low marginal wall of the ring-like magazine. A pusher member which extends beneath the bottom of the magazine, then up through the central stationary hub around which the magazine rotates, then radially toward the projection window, engages the edge of the slide, and pushes it radially into the projection window or gate on the optical axis, through a guide member which is beveled horizontally to receive the advancing edge of the slide and align it properly, and which is pivotally mounted and beveled vertically so as to be thrust aside by vertical axial movements of the magazine when the magazine is inserted in or removed from the projector.

United States Patent 191 Sobotta [45 Feb. 5, 1974 SLIDE PROJECTOR FORRING MAGAZINES V [75] Inventor: Reinhard Sobotta, Mascherode,

Germany [73] Assignee: Roller-Werke Franke & l-leidecki,

Brannschweig, Germany [22] Filed: Sept. 14, 1971 [21] Appl. No.: 180,400

[52] US. Cl. 353/117 Primary Examiner.-Louis R. Prince H AssistantExaminer-A. J. Mirabito Attorney, Agent, or Firm-Charles Shepard 57ABSTRACT A slide projector for use with ring-shaped magazines arrangedhorizontally for rotation about a vertical axis offset laterally fromthe horizontal optical axis. As the magazine rotates step by step, aninclined ramp raises the slide which is to be projected so that itsbottom edge will clear the rather low marginal wall of the ring-likemagazine. A pusher member which extends beneath the bottom of themagazine, then up through the central stationary hub around which themagazine rotates, then radially toward the projection window,

engages the edge of the slide, and pushes it radially into theprojection window or gate on the optical axis, through a guide memberwhich is beveled horizontally to receive the advancing edge of the slideand align it properly, and which is pivotally mounted and beveledvertically so as to be thrust aside by vertical axial movements of themagazine when the magazine is in serted in or removed from theprojector. 1 Y

4 Claims, 4 Drawing Figures 'PAIENI FEB SIBH SHEET 2 HF 2 SLIDEPROJECTOR FOR RING MAGAZINES BACKGROUND OF THE INVENTION This inventionrelates to slide projectors of the kind which use ring-like or annularmagazines for holding a number of slides to be successively projected,and in which the magazine is arranged horizontally for rotation about avertical axis to bring successive slides in the magazine into a positionopposite the picture gate or projection window on the optical axis. Aninclined ramp lifts slides as they approach the projection window, sothat by the time a particular slide reaches a location aligned laterallywith the projection window (i.e., in the projection plane), the slidehas been raised far enough so that its. lower edge will clear the lowouter wall or rim of the ring magazine. Thus the particular slide whichis then to be projected can be transported laterally with respect to thehorizontal optical axis, or radially with respect to the ring magazine,from the magazine itself into the proper picture projection position atthe optical axis.

Such a lift ramp on the projector permits the use of a magazine in whichthe slides are held in their annularly arranged compartments andrestrained'at their two lateral edges between an outer wall or rim andan innr wall or rim of the magazine, so that they cannot accidentallydrop out while the magazine is being handled, unless the magazine isturned upside down. In the case of drum magazines or ring-like magazinesit has been usual, until now, to arrange the magazine with a slot at thepicture-change position, through which slot the picture slide could dropdownward. In the course of this motion, the slide was caught by agripper and was introduced laterally into the picture gate. Afterprojection, the slide had to be moved back to a position beneath themagazine, and then had to be shifted upward into the magazine,whereupon, if the magazine was turned through the next step, thenextpicture slide in the next compartment arrived at the position above thedrop slot. This arrangement requires a rather great total height of theprojector. A certain simplification results if the magazine is arrangedabove the projection gate so that the slide to be projected can dropdown through the slot immediately into the projection position in thegate, without requiring also a lateral movement, and then can be liftedstraight upwardly from projection position into the magazine again, whenprojection of this slide is completed. However, even with thissimplification, a rather great height of the projector is required.

By means of a lift ramp in the guide track of the magazine, a slidearriving opposite the picture gate as a result of the motion of themagazine can be lifted sufficiently far upwardly out of the magazine sothat it can then be shifted laterally into the picture gate orprojection window at the optical axis. This can readily be done withstraight-line magazines or bar magazines, since the magazine is insertedin or removed from its guide track on the projector by a straighthorizontal or axial movement, and therefore it does not matter if aguiding member for guiding the lateral shifting movement of the slidehappens to overlie or overlap the edge of the bar magazine. But if theprinciple is applied to a projector using horizontally arranged ringmagazines (also called annular magazines or drum magazines) severaldifficulties or disadvantages result, and it is an object of the presentinvention to overcome such difficulties or disadvantages.

Whereas in the case of a bar magazine or straightJine magazine, it issufficient to stop the slide gripper in the transport position of themagazine or in the magazine or in the magazine change position in such amanner that it makes the passage of the slides and of the magazine inthe axial direction possible, this meets with difficulties of operationin the case of drum or ring magazine projectors. The slide guide at thepicture gate or projection window has to be brought immediately (i.e.closely) to the side edge of the magazine if a safe and reliable changeof the slide is desired. In doing this, the picture slide guidenecessarily overlaps the adjacent edge of the magazine. In the case of abar magazine, this is not a disadvantage; in fact, it is even anadvantage, because thereby the exact guidance of the magazine can beobtained, which prevents tilting of the magazine, especially in the caseof rather long magazines of the bar or straight-line type. Such a slideguide at the picture gate is necessary for the sake of accurate guidanceof the picture slide in its transfer or shifting movement from themagazine into the picture window at the optical axis, and is desirablealso for the sake of preventing tilting of the magazine, especially inthe case of long bar magazines.

However, the use of such a construction is difficult in the case of aring magazine as distinguished from a bar magazine, as already partiallyindicated above. First, care has to be taken that the slide gripper canbe brought into a position in which the axial lifting out or insertionof the magazine is not impeded. Moreover, it is required that the slideguide at the picture window is formed in such a way that it also doesnot prevent the insertion or removal of the magazine, which is insertedor removed by motion in the direction of the axis on which it rotates.Thus when speaking of a ring type or drum type magazine which isarranged horizontally, axial motion is understood to mean verticalupward or downward motion in the direction of the vertical axis on whichthe magazine rotates step by step when feeding successive picture slidesto the projection position. But when speaking of bar type orstraight-line type magazines, axial motion is understood to mean motionin the direction of the longitudinal axis of the magazine, which isparallel to and offset laterally from the optical axis or projectionaxis. It is seen that if a slide gripper or a slide guide structureoverlapped part of a bar magazine, it would not prevent the axialmovements of the magazine which are necessary when inserting a magazineinto the projector or removing; it therefrom. But if either a slidegripper or a portion of a slide guide were to overlap part of a ringmagazine as distinguished from a bar magazine, then it is seen that thiswould impede the necessary axial (i.e. vertical movement which themagazine must perform when removing a magazine from the projector orinserting a magazine into the pro jector.

These difficulties and disadvantages are avoided by a constructionaccording to the present invention. According to the invention, thehorizontally acting slide gripper structure extends radially beneath themagazine guide track, then comes up through the central aperture in theannular magazine to approximately the elevation of the top of themagazine (preferably extending up through a stationary central hub onwhich the ring magazine rotates) and thence extends horizontallylaterally toward the optical axis, at an elevation appropriate to engagethe lateral edge of the slide which is to be shifted into the projectionwindow at the optical axis, to cause such shifting of the slide.Moreover, the slide guide at the picture gate or projection window hasjaws which are hinged and are spring biased so that they normallyoverlie the adjacent side wall of the ring magazine, to come normallyvery close to the adjacent lateral edge of the slide which is to beprojected, but because of the hinged construction the guide jaws can beswung aside, laterally toward the optical axis and away from the edge ofthe magazine, so as not to interfere with the axial removal andreplacement motions of the magazinefln addition, the guide jaws havevertical bevels or cam surfaces which are engaged by the magazine duringthe axial movement of the magazine, to push the guide jaws asideautomatically when a magazine is lifted axially out of the projector orwhen a new magazine is inserted axially into the projector. Moreover,the slide guide jaws carry a portion which engages with the resilientinner gripper jaw so that the latter is automatically removed from themagazine area by the automatic movement of the guide jaws when themagazine is axially removed or replaced. The guidance of the magazineagainst lateral displacement is preferably provided by a compactstationary cylinder in the central aperture of the magazine, whichcylinder is provided with slots for the passage and the guidance of thegripper.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of aprojector according to a preferred embodiment of the invention, with thering magazine in place thereon;

FIG. 2 is a fragmentary vertical section in the plane of the pictureprojection window or gate of the projector, and radially through aportion of the magazine;

FIG. 3 is a perspective view illustrating details of the grippermechanism or carrier mechanism for shifting a picture slide from themagazine to the projection window or gate, or vice versa; and

FIG. 4 is a top plan view ofa portion of the magazine and associatedparts of the slide guide and the gripper mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT The magazine 2 of ring form orannular form (also sometimes called a drum magazine) lies flathorizontally in an annular recess in the low flat housing or casingportion 1 of the projector. The dimensions of this housing portion 1 ofthe projector have to exceed the diameter and the height of the magazineonly by insignificant amounts, so that this housing portion 1 can berelatively small. The height of the magazine can be and preferably isless than the height of the picture slides contained therein, so thatwhen the slides are in the usual radially arranged slots of themagazine, the upper parts of the slides project upwardly above the topsurface of the magazine itself. Thus the top surface of the magazine maylie at approximately the same elevation as the optical axis (projectionaxis) which extends horizontally through the conventional lens in theconventional lens tube 51, in the somewhat higher portion 5 of theprojector housing or casing.

In the guidance track of the magazine (that is, in the bottom of theannular recess in which the magazine rests) there is an inclined liftramp 3 in a position opposite (that is, in lateral alignment with) thepicture projection gate or window. As the ring magazine turns step bystep to bring successive slides to a position opposite the projectionwindow, the lift ramp engages the bottom edges of the slides approachingthe projection window and lifts the slides so that by the time aparticular slide has reached the position aligned with the projectionwindow, this slide is raised to the position shown in broken lines inthe FIG. 2, where the bottom edge of the slide is just above the topedge of the low marginal rim or flange 4 around the outer periphery ofthe magazine. When the picture slide is in this elevated position, itcan be shifted laterally into the projection gate or window in thehigher portion 5 of the projector housing and similarly shiftedlaterally back at this same elevation into the magazine again whenprojection of this particular slide is completed. When the slide is notin the vicinity of the projection window, it is not lifted upwardly bythe ramp 3 and it rests on the partial bottom of the ring magazine, heldagainst radially outward movement from the magazine by the low outer rimwall 4 and held against radially inward movement by the higher innerwall of the magazine. The inner wall and outer wall of the magazine areconnected to each other and held rigidly with respect to each other bythe radial partitions which subdivide the magazine area into individualcompartments for individual slides, in the familiar manner.

The projector casing part 5, which contains the lens and the picturegate or projector window (of conventional construction) is necessarilyhigher than the casing portion 1 which contains the ring magazine, butis higher only by a relatively small amount, so that a very compactconstruction is provided. As already memtioned, the dimensions of thepart containing the magazine are determined for all practical purposesby the dimensions of the magazine. The height of the part 5 has to behigher than the part 1 only by a sufficient amount to accommodate theheight of a slide after the slide has been lifted by the ramp 3sufficiently far to clear the low outer edge 4 of the magazine. Thewidth of the casing part 5 is determined by the space needed to containthe driving mechanism and other parts necessary in the projector, in sofar as these parts are not arranged in the casing portion 1 around themagazine.

At the edge of the magazine and in lateral alignment with the projectionwindow there are guiding jaws 6 and 7 (FIG. 4) with horizontally bevelededges 8 and 9 acting as cams to insure that the advancing edge of thepicture slide, when being shifted from the magazine toward theprojection window, will properly enter the guidance channel 81 leadingto the projection window. For safe operation and to prevent possiblejamming, the guiding jaws 6 and 7 must be brought as close as possibleto the outer edge of the slide, and therefore, in the normal position,these guiding jaws 6 and 7 overlie or overlap the peripheral retainingedge or wall 4 of the magazine, as seen in FIG. 2. In order that theseguiding jaws 6 and 7 do not impede the axial vertical movements of themagazine when the magazine is being lifted out of the projector orinserted in the projector, the jaws 6 and 7 are not stationary but areswingable on the pivot pin 10 (FIG. 2) and are pressed by a conventionalspring 61 laterally toward the center of the magazine, to the limitposition illustrated in FIG. 2 where they overlie the edge 4 of themagazine.

In addition to being horizontally beveled at 8 and 9 to guide thepicture slide into the projection channel, these jaws 6 and 7 are alsovertically beveled at 11 and 12, at bottom and top, respectively, asshown in FIG. 2. If the magazine is drawn upwardly to remove it from theprojector, the upper edge of the outer wall 4 of the magazine willengage the lower bevel 1 l of the jaws and swing these jaws outwardlyaway from the center of the magazine, on the pivot pin, against thespring pressure. Similarly, when a magazine is being inserted into theprojector, the descending edge of the magazine will engage the upperbevel 12 of the jaws and swing them out so that they do not interferewith'placing the magazine in the projector. When the magazine becomesseated in its proper position, the spring pressure will cause the jawsto snap inwardly toward the center of the magazine, to the normalposition overlying the top edge of the rim 4.

It will be noted from FIG. 4 that these jaws 6 and 7 extend for somedistance circumferentially of the magazine, in each direction from theprojection plane. This is to prevent accidental displacement, if theprojector is tipped, of those slides which have been raised by the ramp3 as they approach the projection plane. In other locations, somedistance from the projection plane, the slides are not affected by theramp 3 and are lower down in the magazine, held against lateraldisplacement by the edge 4, and so would not fall out if the projectoris somewhat tilted. But where the slides have been raised by the ramp 3,the circumferentially extended jaws 6 and 7 serve to maintain the slidesin place.

The mechanism for shifting the slides laterally (radially with respectto the magazine and transversely with respect to the optical axis) fromthe magazine to the projection window or gate in the optical axis, orback from the projection window into the magazine, is illustrated inFIG. 3. Certain conventional parts known in the art are partiallyillustrated in this view, but not specifically identified by referencenumerals and will not be described. The slide shifting mechanismcomprises essentially a U-shaped gripper 13 which engages the innervertical edge of the slide (that is, the edge closest to the center ofthe ring magazine and farthest from the optical axis) working incooperation with a companion gripperjaw 14 which engages the outervertical edge of the slide (that is, the edge farthest from the centerof the magazine and closest to the optical axis). The grip per 13 is ofapproximately U-shape with the U laid on its side, having a longhorizontal leg which extends from the operating mechanism within theportion 5 of the projector housing, laterally beneath the bottom of themagazine to a point near the center of the magazine, then a vertical legextending upwardly through the central aperture ofthe magazine, and thenanother horizontal leg extending from the top of the vertical leghorizontally toward the optical axis, at an elevation just above the topof the magazine. Since the particular slide to be shifted from themagazine to the optical axis has already been raised by the ramp 3, theupper horizontal leg or arm of the member 13 is at an elevation toengage the vertical edge of the picture slide approximately midway ofits height, as seen in FIGS. 2 and 3, where the picture slide which isabout to be shifted is shown in broken lines at 16.

The previously mentioned other jaw 14 of the slide shifting mechanism,which enages the vertical outer edge of the slide, is mounted on thelong lower horizontal arm of the member 13,. slidable longitudinallythereon to a limited extent, and urged by a spring 15 in a directiontoward the upper arm of the member 13. As seen in FIG. 3, the grippingmember 14 has a vertical groove which is V-shaped in horizontal section,suffciently elongated vertically to engage most of the height of theouter vertical edge of the particular picture slide which is to beshifted between the magazine and the optical axis. The upper arm of theother gripper 13, on the other hand, has a V-shaped notch which engagesthe inner vertical edge (edge closest to the center of the magazine) ofthe slide at a point roughly midway from top to bottom, and keeps theopposite vertical edge seated in the groove of the opposite member 14,under the tension of the spring 15. Thus the slide to be transported orshifted is clamped between these two parts 13 and 14.

Assuming that a slide is in projection position at the optical axis andthat the slide is to be changed so that another slide can be projected,the slide gripping or shifting mechanism moves in the direction of thearrow A in FIG. 3. Immediately before the advancing edge of the slide(the left edge when viewed as in FIG. 3) hits the inner wall of themagazine and can not be moved any further, the jaw 14 is prevented frommoving further by a stop so that it stops outside the area of the slide.The companion gripper jaw or point 13, however, moves further leftwardlya slight distance, until it also is outside the area of the slide. Thisdisengaging stroke may also be used, as known in the art, for steppingor feeding the magazine through one step. The slide which has just beenreleased is carried around with the turning of the magazine, and movesout of the projection plane. If it is not already seated against theinner edge wall of the magazine, the horizontally beveled cam portion 8or 9, as the case may be (depending upon the direction of rotation ofthe magazine) will engage the outer vertical edge of the slide and shovethe slide radially inwardly toward the center of the magazine.

When the next slide reaches the projection plane as a result of rotationof the magazine through one increment, the gripper point 13 then movesto the right when viewed as in FIG. 3, toward the jaw 14 which has beenheld by its stop above mentioned. In so doing, the gripper point 13engages the adjacent vertical edge of the slide 16, and moves the sliderightwardly, through the guiding cam parts or beveled parts 8 and 9 ofthe jaws 6 and 7, and into the groove of the gripping jaw 14, and themotion continues in a rightward direction, with the picture slidegrasped between the jaws l3 and 14, until the picture slide is properlycentered in projection position at the optical axis. The picture slideremains gripped between the jaws 13 and 14 while projection takes place.

It has been mentioned above that there is a stop which stops theleftward motion of the jaw 14 when the projected slide is brought backto the magazine. Preferably this stop is provided by the jaws 6 and 7which are in a position to be engaged by and form abutments preventingfurther leftward movement of a portion of the member 14. In this manner,it is possible that if the magazine is drawn out axially to remove itfrom the projector, the engagement of the magazine with the beveledportion 11 of the jaws 6 and 7 will not only swing these jaws radiallyoutwardly to allow the magazine to pass, but also the outward motion ofthe guiding jaws 6 and 7 will cause a slight outward movement of thegripping jaw 14 against the tension of its spring 15, insuring that thisjaw is moved back far enough so that it cannot interfere with the axialupward movement of the magazine which is being taken out of theprojector. The other gripping jaw 13 also does not impede the removal orinsertion of the magazine, because the jaw 13 has come to rest in aposition entirely within the outline of the central opening of themagazine, and does not overlap or overlie any part of the magazine.

The gripper part or shifting part 13 can also be equipped with a handle18, if desired, so that the shifting mechanism can be grasped andactuated by hand.

The central space of the ring magazine is preferably occupied by astationary hub member 17 which is part of the projector housing, thishub member 17 having a diametrical slot for passage of the upstanding orvertical arm of the gripper or shifter member 13. The guiding of thering magazine in its rotary motion can be provided entirely by acircular track on which the bottom of the magazine rests, or partly bysuch a track and partly by the hub which rises through the center of themagazine.

Other parts of the projector, such as the driving mechanism, may be ofany form known in the art, the details of which are not important forpurposes of the present invention. Some of the features may, forexample, be of the form disclosed in German patent application(Offenlegungsschrift) no. 1,802,546.

What is claimed is:

l. A picture slide projector for use with horizontally arranged ringmagazines, including means for mounting a ring magazine in position tobe removed from the projector by a substantially vertical upward axialmovement and to be replaced in the projector by a substantially verticaldownward axial movement, said mounting means mounting said magazine forrotation about a substantially vertical axis to bring successive slidesin said magazine to a position aligned with a projection window so thatan aligned slide may be shifted laterally from such aligned position tosuch projection window, characterized by the provision of a slide guidemember in the immediate vicinity of the slide which is to be shiftedfrom the magazine to a projection position, said slide guide memberbeing mounted for radial movement toward and away from the ring magazineand being resiliently urged toward the magazine to a normal operatingposition in which it overlies a portion of the magazine.

2. A projector as defined in claim 1, in which said slide guide memberis pivotally mounted to swing toward and away from the magazine.

3. A projector as defined in claim 1, further including cam means formoving said slide guide member radially away from the magazine as saidmagazine is moved axially upwardly or downwardly to remove it from orplace it on the projector.

4. A projector as defined in claim 3, in which said cam means comprisesbevel portions (11, 12) at top and bottom of the slide guide member.

' UNITED STATES PATENT OFFICE CERTIFICATE OF CORRE ITION Patent3,790,269 Dated February 5, 1974 Inventor(s) REINHARD SOBOTTA It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the cover sheet [73], the assignee should reed as follows:Rollei-Werke Franke G Heidecke, Brannschweig,

Germany 0n the cover sheet, insert [30] Claims Foreign Priority DataGermany -P 20 45 661.5 Sept. 16,1970

Signed and sealed this 13th day of August 1974.

(SEAL) Attest:

' MCCOY M. I GIBSON, JR. C. MARSHALL DANN Attesting Officer Commissionerof Patents FORM PO-105O (10-69) USCQMM-DG 60316-P69 w u.s. GOVERNMENTPRINTING orrlci "I! o-ui-au.

1. A picture slide projector for use with horizontally arranged ringmagazines, including means for mounting a ring magazine in position tobe removed from the projector by a substantially vertical upward axialmovement and to be replaced in the projector by a substantially verticaldownward axial movement, said mounting means mounting said magazine forrotation about a substantially vertical axis to bring successive slidesin said magazine to a position aligned with a projection window so thatan aligned slide may be shifted laterally from such aligned position tosuch projection window, characterized by the provision of a slide guidemember in the immediate vicinity of the slide which is to be shiftedfrom the magazine to a projection position, said slide guide memberbeing mounted for radial movement toward and away from the ring magazineand being resiliently urged toward the magazine to a normal operatingposition in which it overlies a portion of the magazine.
 2. A projectoras defined in claim 1, in which said slide guide member is pivotallymounted to swing toward and away from the magazine.
 3. A projector asdefined in claim 1, further including cam means for moving said slideguide member radially away from the magazine as said magazine is movedaxially upwardly or downwardly to remove it from or place it on theprojector.
 4. A projector as defined in claim 3, in which said cam meanscomprises bevel portions (11, 12) at top and bottom of the slide guidemember.